This invention relates, generally, to optics, and more particularly, to coupling of optical fibers to a waveguide.
At present, an optical fiber or optical fibers are coupled to optoelectronic devices by a multistep process. First, an end of the optical fiber is aligned or positioned to an end of a core region of a waveguide. Second, once the end of the optical fiber is aligned to the core region of the waveguide, the end of the optical fiber is affixed to the core region of the waveguide, thus permanently fixing the optical fiber to the core region of the waveguide.
Generally, the alignment of the end of the optical fiber to the core region is accomplished by either an active or a passive alignment procedure. The active alignment procedure requires that a light signal be passed through the optical fiber and the core region of the waveguide, as well as having the light signal being detectable when the optical fiber and the core region are aligned. Once the optical fiber and the core region are aligned, the optical fiber is held and cemented or affixed in place. However, active alignment has several disadvantages, such as being labor intensive, being slow, and having a high cost, thus making active alignment an unattractive approach in a high volume manufacturing environment.
Alternatively, the passive alignment procedure aligns the optical fiber to the core region by mechanically placing the optical fiber to the core region of the waveguide. However, as passive alignment is presently practiced, passive alignment has several disadvantages such as poor alignment quality that results in poor quality of product as a whole or a product that is defective and cannot be sold, thus resulting in the product having a high cost. Further, passive alignment requires that machining tools and alignment tools have extremely high alignment and positioning tolerances and accuracies, thus further increasing the cost and difficulty of manufacture in a high volume manufacturing environment.
By now it should be apparent, that the presently used coupling methods for connecting optical fibers to waveguides have several problems that severely limit their use in a production environment. Further, it should be pointed out that alignment of optical fibers to waveguides typically is achieved by aligning the optical fibers to the core region by hand, thus incurring a high cost in manufacturing of coupling optical waveguides to optical fibers. Thus, a method for connecting optical fibers to waveguides that is cost effective and manufacturable in a high volume environment would be highly desirable.